Valve for rock drills



I y 1931- c. C..HANSEN 1,805,695

' VALVE FOR ROCK DRILLS Filed April 9. 1927 INVENTOR.

(12 02*, ea Cyan 6'62;- BY

211,5 ATTNEY.

v the rearward,

"UNITEDVYIISTATELS PATENT OFFICE,

CHARLES C. HANSEN, I EASTON, PENNSYLVANIA, ASSIGNOR TO INGEBSOLL-RAND COMPANY, OF JERSEY CITY, NEW JERSEY,

A CORPORATION OF NEW JERSEY 4 VALVE FOR ROCK DRILLS" 1 'n n anqn filed April .9, 1927; Serial No. 182,322.

This invention relates to rock drills, but more particularly to a distributing valve for a fluid actuated rock drill of. the hammer y 7 1 7 '7 J The objects of' the invention are to obtain a light weight 'valve capable of effecting a rapid distribution of'the pressure fluid'to the ends of the cylinder and to insure against trembling of the valve in its extreme posi- 10 tions.

in part pointed out hereinafter. u In the drawings 'illustratinga practical embodiment of the invention; I Figure 1 is a longitudinal vertical section of a rock drill 'showingthe valve in one extreme position, and

ing the valve in its other extreme position.

Referring to the drawings, the invention is shown embodied in a rock drill comprising a cylinder Ahaving a free exhaust port B. A

reciprocatory hammer-piston is disposed in the cylinder A and controls the free exhaust port B. In the present instance a back head D forms a closure for the rearward end of the cylinder and is 'adapted to overlap the 'rearward'end of avalvechestE. The valve chest E maybe formed integrallywith the cylinder A as shown and has an annular re- I are disposed valve bushings J and K bored to form a valve chamber L for a pressure fluid distributing valve 0. v r

In order to centralize the bushings J v andK with respect to each othenthe bushingtJ is provided with a short reduced extension P which extends intothe rearward end of the bushing By so reducing the end of the bushing J a shoulderfQ, is provided toabut cess F in which 4 the rearward end of the bushing Kv forholding said bushingK fi l in the florzwardgend 0f the recess I 1 v V The total lengths ofthe two bushings thus arranged preferably substantially equals the depth of the recess F so that when the back head D is clampedtofthecylinder A by the usual sidebolts (not shown), the said bush ings will beheld firmly inoperative position by the back-head which, in this instauce, abuts w f the bushing Prefer r w y I of pressure fluid into the drill, "Other objects will. be in part obvious and V V v valve chamber L 1s formed'an inletj'passage Figure 2 1s a new similar to Figure 1 show-7' "passage V.

likewise reduced to afre-cess formed'in the front endof the? "bushing ably a projection is formed on the rearward I end of the bushing J to extendinto an annular recess S in the back head D for preventing v leakageof pressure fluid from apassa'ge T 1n the bushing J andthe back head D.- The passage in this instance is inconstant communication with the valve chamber L and also with a throttle valve U in the back head, said throttle valve controlling the admission At the juncture of the passage Txand the V which leads to the rearw'arden'd of the cylinder A. Likewise,"an inlet'pass'age W'leads 1165 "the front end of the cylinder Afor conveying from the front end of the valve chamber L to in this instance passing from the front end of the valve chamber L into the inlet passage "W through ports Y in the end" of'the'bu'shing K. i

Intermediate the ends of the valve is formed an enlarged flange Z having rearward and forward actuating pressureareas b and c 'respectively, 'The enlarged flange Z is preferablyjof slightly greater length than the'fwidth (if an exhaust port d in thelvalvef chest whichit controls. f v

The rearward end'e of the valve O'is'in thisjin'stance reduced in diameter to enable said 'endto extend slidably into a recessg 'of the bushing "J for controlling communication between the passage T and the inlet cooperateslidablywith K for controlling communicationbetween the front end of the valve chamber-L and the front inlet passage'W. By thus reducing the ends of the valve, annular shoulders h are formed on the'valve against which pressure fluid may act for holding the valve in'its extreme positions; I

he valve 0 is actuated by live pressure fluid admitted into the valve chamber L on ep'po'site sides'of flange Z at the most The ,front end fof thevalve O suitable period in the cycle of operations of the drill. To that end a kicker port j is formed in the valve chest and leads from a point forwardly of the free exhaust port B to communicate with the valve chamberL rearwardly .of the actuating face 6 of the flange Z, and a kicker passage 70 leads from the cylinder rearwardly of the exhaust port B to the valve chamber L forwardly of the 10 actuating pressure area 0 for actuating the valve 0 rearwardly.

In order to prevent centralizing of the valve O, said valve is provided with suitable leak ports 0 through which pressure fluid may constantly leak into the valve chamber to act against the actuating pressure areas 5 and 0 toset the valve in operation. r Should the valve 0 assume a neutral position before the drill is set in motion, it will be apparent that the reduced ends of the valvewill each be slightly within therecesses -gandthus prevent pressure fluid from passing over these ends and entering the cylinder to start the piston.

Assumingthatthe valve is centralized and the-flange Z thus covering the exhaust port and if the pistonC is in theposition shown in Figure 1 with the kicker port 70 covered,

' pressure -flui cl '-entering the hollow valve 0 V will pass through the leak ports 0 to opposite sides of the flange Z. 'Thepressure fluid which enters the lower leak port 0 will .pass through the kicker port and exhaust through the free exhaust port B.

The pressure fluid which passes through the upper leakport 0 will, however, act upon the pressure area-c to .throw the valve, as the kicker port. 70 is covered by the piston and the flange Z covers the exhaust port (Z. The tool will thereby beset in motion. V Inasmuch as the kicker ports j andJcare ;so spaced that they may not be simultaneous jlycovered by the pistonC, even though the -piston C overlies {the exhaust port 13,111; may .happenfthat the piston will assume a .position intermediate these kicker ports without vcovening'either; If the-valve then is central- ;ized, it will also be evident that pressure 80 fluid may pass through the leak ports only and enter both ends of .the cylinder through thetwo kicker ports j-and k. However, due to thediiference in area between the front and 'rear faces of the piston C, the'pressure fluid entering the rear of the piston through kicker port j will build up pressure which will act upon the ,rear face to overcome the pressure acting upon thefrontface and thus move the piston until 0 the kicker port is is covered thereby. The ;pist on will now .bein theposition shownin Figure 2 and, as described, the valve will ,be moved by pressure fluid acting upon the P es ur area v it il be appa ent, he f e-th t thelea ports 0 will prevent the valve 0 from re phere.

maining centralized should this condition occur when the tool is to be set in operation. The piston may assume a variety of positions when the valve is centralized but, as will be seen from the instances described, the leak ports will immediately permit pressure fluid to pass and cause the piston to move to a position where one or the other of the kicker ports will be covered whereupon the valve will be moved from its centralized position.

As will be observed, the distance which the reduced ends of the valve extend into the recesses 'g is slightly smaller than the travel of-the valve required toopen communication between thevalve chamber and the exhaust port d. In this-way asupply'ofpressure fluid will "at all times be assured to ,act againsttheslioulders h for holding the valve in thrown position.

The'operationof the .device isas follows: Vhile the valve 0 is in the position illustrated in Figure 1, [pressure fluid flowing through the passage T will pass through ,the nlet passage V to the rearward ,end of the cylinder and actuate the piston forwardly. T he-pressure'fluid thusflowingintO t e cylinder will act against therearward shoulder h the valve and hold the valve O firmly in ts extreme forward position. piston C uncovers the kicker passage a por ion of pressure fluid will flow into the valve oham'berL to act against the'actuating pressure area c for 's'tartingthe valve rearwardly. After the valve 'has traveled a slight distance in this direction, theexhaust port cl will be uncovered'by-the flange Z the pressure fluid utilized for starting the valve will then be exhausted to the atmos- -After the valve has been thrown rear- .wardly,pressure fluid will flow over the front end thereof and,.passing through the ports Y, front-inlet passage W; into the frontend of the cylinder will impel the piston -C rearwardly. However, us't .prior to uncovering of the port Id the'end f will have been with- -dra wn from the recess g and pressure fluid then flowing from the front end'ofthe valve ;wi ll;act,thereagainst, as well as the front shoulder ,h, to complete the rearward'ltravel .of the valve and to hold it in the new position. In this way a comparatively large-area of the valve is'exposed to pressure flui' d for setting it in motion and a considerably smaller area is exposed tofluidffor completing the stroke of the valve. The valve is thus exposed to a pluralityof impulses for throwing it and inasmuch Lthatthe latter of these impulses is a comparatively light force the valve will be prevented from striking e y ag ins it s p- T si particula y .a a aseeu l a es ha in 1% lens r n o t a .Dlllliig uc admissio 1 re 'sur fluid will then actagainst the front s 'oulder h to hold the valve immovable in its rearward position. a 1

Immediately prior to the uncovering of the free exhaust port B, the front kicker passage 7' will be uncovered by the piston, and the pressure fluid under full line pressure will then flow through the passage j into the valve chamber L to act against the actuating pressure area b .to again start the valve for wardly and after the flange Z uncovers the exhaust port d the pressure fluid flowing over the rearward end of the valve will act against said end and against the rear shoulder h to complete the forward movement of the valve and to hold it in the forward position.

I claim:

1. In a fluid actuated rock drill, the combination of acylinder and a piston, a valve upon ' chest in the cylinder chest in the cylinder having an exhaust port therein, a hollow distributing valve in the valve chest through which pressure passes, said valve being movable back and forth in the'valve chest to admit pressure fluid to one end or the other of the cylinder, a flange on the valve controlling said exhaust .port and having relatively large actuating pressure areas upon which pressure fluid from the cylinder may act to move the valve, said movement of the valve serving to partly uncover the exhaust port and permit the exhaust of pressure fluid acting on said actuating pressure areas, reduced ends on the valve adapted to alternately engage the valve chest and prevent fluid over said shoulders defined by said reduced ends on the valve, said shoulders and the end surfaces of the valve forming relatively small actuating pressure areas upon which pressure fluid may act and complete the-movement of the valve whenthe exhaust port is uncovered bythe flange.

2. In a fluid actuated rock drill, the combination of a cylinderand a piston, a valve havingan exhaust port therein, a hollow distributing valve in the valve chest throu h which pressure fluid passes, said valve loeing movable back and forth in the valve chest to admitpressure fluid to one end or the other of the cylinder, a central flange on the valve controlling said exhaust port and having relatively .large actuating pressureareas on each side thereof which pressure fluid from the cylinder may act to move the valve, said movement of the valve serving to partly uncover the ex haust port and permit the exhaust of pressure fluid acting vent the admission of pressure fluid over said ends to the cylinder, and shoulders defined the admission of pressurev ends to the cylinder, and P on said actuating pressureareas, kicker passages in the cylmder'and by said reduced ends on the valve, said shoulders and the end surfaces of the valve forming relatively small actuating pressure areas upon which pressure fluid may act and complete the movement In a fluid actuated rock drill, the com bination of a cylinder and a piston, a valve chest in the cylinder having an exhaust port therein, a hollow distributing valve in the valve chest through which pressure fluid passes, said valve being movable back and forth in the valve chest to admit pressure fluid to one end or the other ofthe cylinder, a flange on the valve controlling said exhaust port, reduced ends on the valve adapted to alternately engage the valve chest and prevent the admission of pressure fluid over said ends to the cylinder, valve through which pressure fluid passes to actuate said valve and start the drill when both ends of the valve are simultaneously engaged by the valve chest. I

4. In a fluid actuated rock drill, the combination of a cylinder and a piston, a valve chest in the cylinder having an exhaust port therein, a hollow distributing valve in the valve chest through which pressure fluid passes, said valve being movable back and forth in the valve chest to admit pressure fluid to one end orthe other of the cylinder, a flange on the valve controlling said exhaust port and having relatively large actuating from the cylinder may act to move the valve, said movement of the valve serving to partly uncover the exhaust exhaust of pressure fluid acting on said actu ating pressure areas, reduced ends on the valve adapted to alternately engage the valve chest and prevent the admission of pressure fluid over said ends to the cylinder, shoulders defined bysaid reduced ends on the valve, said shoulders and the end surfaces of the valve forming relatively small actuating pressure areas upon which pressure fluid may act and complete the movement of the valve when the exhaust port is uncovered by the the valve through flange, and leak ports in which pressure fluid passes valve and start the the valve are simultaneously valve chest.

to actuate said engaged by the In testimony whereof I have signed this specification.

7 CHARLES C. HANSEN.

of the valve when the exhaust port is uncovered by the central and leak ports in the c ressure areas upon which pressure fluid a port and permit the drill when both ends of e 

